INFERRING BIOLOGICAL EVOLUTION
from FRACTURE and WEAR PATTERNS
in TEETH
4 p.m. Thursday, May 5 • Hill Hall 202
ABSTRACT How tooth morphologies impact on evolutionary
BRIAN LAWN
NIST Fellow Emeritus
National Institute of
Standards and Technology
Gaithersburg, MD
adaptation in fossil and living species is considered from the viewpoint
of a biomaterials scientist. Teeth are critical markers of our past and
present, how we eat, how we survive. They are relatively hard and
brittle with complex microstructures. It is hypothesised that specific
tooth forms are adapted to resist fracture and wear in order to
accommodate the high bite forces needed to secure, break down and
consume food. Distinct modes of tooth fracture are identified and
quantified. The micromechanics of wear are also briefly analyzed in
the context of abrasive particulates in the food source. Attention is
given to the relatively flat molars of omnivorous mammals, including
humans and other hominins, and to the elongate teeth of carnivores
and herbivores. The lecture is presented as an illustration as to how the
materials scientist may reach out to such disparate fields as biology and
dentistry.
ABOUT THE SPEAKER Brian Lawn gained B.Sc. and Ph.D. degrees in Physics at the University of
Western Australia in 1959 and 1963, respectively. He then spent four years as a postdoctoral fellow in the
School of Physics at the University of Bristol and the Department of Engineering and Materials Science at
Brown University. From 1968 to 1981, Dr. Lawn was a professor in Physics at the University of New South
Wales. In 1981, Dr. Lawn joined the National Institute of Standards and Technology, and in 1987 was appointed
to the position of NIST Fellow. He has held Adjunct Professor appointments at several universities worldwide.
Dr. Lawn is the author of the text “Fracture of Brittle Solids”, first published in 1975 and now in its second
edition. In 2001, he was elected to the U.S. National Academy of Engineering, and in 2012 to the Australian
Academy of Science. He was awarded an Honorary Doctorate in Engineering by the University of Western
Australia in 2008. Dr. Lawn is a Distinguished Life Member of the American Ceramic Society.